Protective device with terminal clips thereon



Aug. 28, 1962 s. v. DELL 3,051,809

PROTECTIVE DEVICE WITH TERMINAL CLIPS THEREON Filed Aug. 27, 1959 FlG.l

FIG.2

A? INVENTOR.

FIG.7 SAUL V DELL ATTYS.

United States Patent 3,051,309 PROTECTIVE DEVTCE WITH TERMINAL CLIPS THEREGN Saul V. Dell, Akron, Ohio, assignor to Mechanical Industries Production Company, Akron, Ohio, a corporation of Ohio Filed Aug. 27, 1959, Ser. No. 836,505 2 Claims. (@111. 200-138) The present invention relates to terminal means, and especially to the combination of a lead with a novel terminal member in an electrical protective member, such as motor protectors, thermostats, or the like, and to the particular construction of the terminal member.

In securing small electrical leads to electrical protective articles, such as thermostats, it always is diflicult to obtain an effective electrical contact between the lead and terminal means in the thermostat or other member. These leads in some instances are subjected to repeated flexing actions adjacent the terminal of the thermostat or other article, and it is important that these leads and terminals be in good permanent electrical engagement to provide a long service life in the thermostat. The desired construction is such that the lead and terminal connection does not give any difficulty in the electrical circuit until other portions of the electrical protective member or of the circuit have had failures occur therein. It also is very desirable to eliminate or reduce the number of parts and the number of welds and assembly steps required in making electrical protective members.

The general object of the present invention is to provide a novel and improved thermostat, motor protector, or similar member characterized by the provision therein of a metal terminal strip operatively carried by the member and having a bifurcated end extending therefrom with end loops provided therein for receiving and securing a lead to the terminal strip.

Another object of the invention is to provide a terminal strip in a thermostat or similar article wherein two transversely spaced looped sections are provided in the terminal at the end thereof with a lead extending loosely through and being partially positioned by one loop section and with the end of the lead being effectively permanently secured to the second loop section of the terminal strip.

Yet another object of the invention is to provide a section in a terminal strip for aiding in distributing some or the flexing action of a lead with relation to a portion of the lead secured to the terminal strip.

It is another object of the invention to avoid variable resistance connections between terminals and operative control arms in a motor control or other electrical protective or control means.

Further object of the invention are to provide an improved terminal and lead connection for small electrical articles; to provide a guide loop in a terminal assembly to remove direct stresses on a connection between a terminal and a lead; to provide a terminal integral with and aligned with an operative current carrying arm in an electrical control; to reduce the thickness of a case for an electrical control; to reduce the number of assembly operations in making an electric control; and to provide a terminal and lead connection that is uncomplicated but which will have a long service life.

The foregoing and other objects and advantages of the invention will be made more apparent as the specification proceeds.

Particular attention is now directed to the accompanying drawings, wherein:

FIG. 1 is a side elevation of a novel terminal strip embodying the principles of the invention;

FIG. 2 is a plan of the terminal strip of FIG. 1;

3,651,809 Patented Aug. 28, 1962 FIG. 3 is a plan View of a terminal strip operatively associated with a thermostat in accordance with the teachings of the invention;

FIG. 4 is an enlarged vertical section taken on line 44 of FIG. 3;

FIGS. 5 and 6 are vertical sections taken on lines 55 and 6ti, respectively, of FIG. 4; and

FIG. 7 is a side elevation of a modification of the invention.

When referring to corresponding members shown in the drawings and referred to in the specification, corresponding numerals are used to facilitate comparison therebetween.

The present invention relates to the combination in a thermostat or similar article of a case, a metal terminal strip operatively carried by the case and extending therefrom, which terminal strip has a loop with a transversely extending bore formed in its end, and also having a longitudinally extending slot in the strip dividing the loop into two transversely spaced sections, and a lead loosely threaded through the loop portion of one terminal section, and received within and secured to the other of the looped sections to be secured to the terminal thereby. Usually this second loop section is flattened to aid in effectively permanently positioning the lead therein in effective electrical engagement with the terminal strip.

Having particular reference now to the details shown in the accompanying drawings, a metal terminal strip 1 is shown and it has a loop 2 formed in one end thereof. The loop 2 is formed into two transversely spaced sections 3 and 4- by a longitudinally extending slot 5 in the free end of the terminal strip 1 and extending through the loop 2 into the remainder of the end portion of the terminal strip.

The terminal strip 1 of the invention is usually used in association with a small electrical control article such as a motor protector or a thermostat 6, as shown in FIG. 3. The terminal strip 1 may be made from a bimetal material, or from copper, or equivalent conductive material so that it can be positioned in a conventional manner in a case '7 of the thermostat 6 and form part of the operative control therein. Leads 8 and 9 are operatively secured to the thermostat 6 for connecting an electric circuit thereto for control action of the electric circuit. These leads 8 and 9 normally are provided with insulation covers. Usually the leads 8 and 9 must extend from the member, such as the thermostat 6, substantially parallel to the longitudinal axis thereof as the thermostat usually is positioned in confined areas and the leads thus must be bent at substantially angles to the secured end portions thereof in most instances.

It will be seen that the loop section 3 is relatively narnow in width in relation to the wider loop section 4 which has the end of the lead 8 secured thereto for electrical engagement therewith, as hereinafter described in more detail.

FIG. 4 of the drawings best brings out the fact that the lead 8 has the insulation cover removed from an end 10 thereof and with such non-insulated end 10 of the lead 8 loosely extending through the loop section 3. Hence the movement of the end 19 of the lead i limited or controlled by the encompassing loop section 3, and with the remainder 10a of the end 10 being giuded, or positioned to extend transversely of the terminal strip 1.

It is an important feature of the present invention that the end 10 is permanently engaged with the terminal loop section 4. Preferably such loop section 4 is flattened for good electrical contact with the lead end 10, and usually a weld bonds the end 10 to the terminal loop section 4. Of course, the end It) could be soldered, brazed, or merely engaged with, or secured to the terminal loop 5 section 4 by a compression action, or by other means, as desired.

It has been found in constructions of the invention that the fiexure or bending action of the lead 8 is not directly and completely transmitted to the secured end 10 thereof, and that the loop section 3 forms a guide portion in the assembly to limit maximum flexure of the end 10 of the lead, but also permits some flexure over a length of the lead end 16' so that a limited, or completely localized flexure action is not obtained. FIG. 6 best brings out the flattened construction of the loop section 4 when permanently secured, as by welding, to the end 10 of the lead.

The terminal strip 1 has a conventional contact 11 welded or otherwise secured thereto for circuit make and break action in the electrical protective article.

The slot may be located at any desired place transversely of the terminal strip. Of course, a lead may be secured to a terminal strip without flattening the terminal loop 4.

A modified terminal 12 is shown in FIG. 7 and it has a split loop 13, like the loops 3 and 4 formed therein. This terminal 12 would extend into a member, such as the thermostat 6, only to the closed end thereof where it would be secured to an operative arm in the casing, or to the casing of the thermostat, as desired.

It will be seen that the loops 3 and 4, and 13 may extend in only one direction from the plane of the terminal strip so that it will lie flat on a table, or the loops may extend in two directions from the plane of the fiat section of the terminal strip.

The terminal strip 1, whether a bimetal strip or a heater strip, would have a cantilever secetion (not shown) extending into the case 7 for circuit control action therein. Obviously both arms of the electrical control 6 may have the terminal loop and means of the invention formed integrally therewith.

The novel thermostat or similar article provided by the invention has an eifective and permanent engagement between the bifurcated terminal strip and the lead means secured thereto, and either one or both terminal strips in a conventional electric control or protective article can be constructed in accordance with the teachings of the invention. The terminal strip is not diflicult or costly to make, and it can readily have leads secured thereto. Thus it is believed that the objects of the invention have been achieved.

While one complete embodiment of the invention has been disclosed herein, it will be appreciated that modification of this particular embodiment of the invention may be resorted to without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. In combination in an electrical protective article having a longitudinal axis, a case, a metal terminal strip operatively carried by said case and extending therefrom parallel to said longitudinal axis, said terminal strip having a loop with a transversely directed axis formed in its end and a longitudinally extending slot dividing said loop into two transversely spaced sections, and a lead loosely threaded through one of said terminal sections and secured to the other of said sections, said lead extending from said one terminal section at least substantially parallel to the longitudinal axis of said article and having an end portion extending transversely of said article to extend through and engage said sections of said loop whereby fiexure stresses created by movement of said lead are not localized in said lead.

2. In a thermostat or other electrical protective article, a case, circuit control means positioned within said case, a terminal connecting to said circuit control means and extending from said case, said terminal including a flat metal strip having an integral loop formed at its free end, said loop having a bore extending transversely of said strip, said strip having a longitudinally extending slot formed in said loop and extending through said loop into the remainder of said strip to divide said loop into two sections, and a lead conductively secured to said terminal, an end portion of said lead loosely extending through one section of said loop, and terminating adjacent the other section of said loop, said other loop section having said lead end portion received therein and secured thereto, said lead extending from said terminal substantially parallel thereto whereby the connection of said end portion of said lead to the remainder of said lead can b flexed in a loosely confined space along at least the length thereof extending through said one loop section.

References Cited in the tile of this patent UNITED STATES PATENTS OTHER REFERENCES Haas: German printed application 1,023,116, printed Jan. 23, 1958. i 

